But then, if you're planning to fail, you're not failing to plan, so you're not planning to fail; but then...
There are a couple of different ways to fail, I think. Well, no, there's many, many ways to fail. But one of the greatest failures in business might just be relying too much on people, or more specifically, on people's memories.
Especially for annual projects (and at the risk of sounding like a whinger to people I work with - also, if you've found my blog, hi!), it's easy to think that it's over once it's over and you don't then need to think about it again, for another year.
I think there's actually a lot of value in keeping a diary of sorts during a project, because you can then iterate on it - you can do it better next time and not forget what you could've done better this time.
This might not be anything original as a whole, but it would seem to be new to some people.